Rotating stabilisers

A rotating stabiliser electrically connectable to a power grid, the rotating stabiliser comprising:

• a synchronous condenser comprising:
• a first stator assembly with a first stator winding that is electrically connectable to the power grid, and
• a first rotor assembly with a first rotor winding;
• a starter/exciter comprising:
• a second stator assembly with a second stator winding,
• a second rotor assembly with a second rotor winding, wherein the second rotor
• assembly is mechanically connected to the first rotor assembly by a rotor shaft, and
• a first power converter having first terminals electrically connected to the first rotor
• winding and second terminals electrically connected to the second rotor winding,
• wherein the first power converter is mounted for rotation on the rotor shaft;
• and
• a second power converter having first terminals electrically connectable to the power grid and second terminals electrically connected to the second stator winding.